High pressure gas cycle and power plant

ABSTRACT

Provided is a combustion chamber for producing a pressurized gas containing:a wall structure defining an interior chamber;a first reflecting surface for reflecting a pressure wave within said interior chamber;a second reflecting surface for reflecting said pressure wave within said interior chamber, wherein said first and second reflecting surfaces being constructed and arranged to resonate said pressure wave in said interior chamber;at least one first inlet for introducing a first gas into said interior chamber; andat least one outlet from said interior chamber for drawing off a pressurized gas from said interior chamber. Also provided is a turbine engine containing the combustion chamber, and an electrical generating power plant containing the turbine engine.

This application is a Divisional application of U.S. Ser. No.09/669,377, filed on Sep. 26, 2000, now U.S. Pat. No. 6,301,872, whichis a Divisional Application of Ser. No. 09/305,481, filed on May 6,1999, now U.S. Pat. No. 6,167,693, which is a Divisional Application ofU.S. Ser. No. 08/840,476, filed on Apr. 21, 1997, now U.S. Pat. No.5,983,624, the complete disclosures of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a high pressure gas cycle for use in an engine.The invention also relates to an electrical power generating plant.

2. Background of Related Art

The Otto cycle shown diagrammatically in FIG. 1 [Prior Art], withpressure as the ordinate and volume as the abscissa, is a cycle thatclosely represents the explosion and compression stages of a gasolineautomobile engine. In the Otto cycle, the air is drawn in at atmosphericpressure, shown at 1, then compressed isentropically to a high pressurewith fuel mixed in the air, shown at 2. The fuel air mixture explodes ata theoretically constant volume to form a combustion gas having anincreased pressure, shown at 3. The combustion gas expandsisentropically back to the original inlet volume, shown at 4, where thecombustion gas is then discharged. As shown in FIG. 1, the combustiongas discharges at a pressure above atmosphere, shown at 4, and then thepressure drops to atmosphere as it exhausts from the engine, not shown.The energy that could be available by expanding from exhaust pressure toatmospheric pressure, represented by the difference between 4 and 1shown in FIG. 1, is wasted.

The theoretical efficiency of the Otto Cycle is defined by therelationship 1−(V₂/V₁₁) ^((K-1)) where V₁/V₂ is the ratio of the volumebefore compression to the volume after compression, commonly called thecompression ratio. K=ratio of specific heat at constant pressure tospecific heat at constant volume=C_(p)/C_(v).

Another cycle commonly used in automobile engines is the Diesel cycle.The pressure vs. volume diagram for a Diesel cycle is shown in FIG. 2[Prior Art]. In a Diesel cycle, air is drawn in at atmospheric pressure,shown at 5, and then the air is compressed, shown at 6. The fuel isinjected after the air is compressed and burns at somewhere nearconstant pressure to form a combustion gas, shown at 7. The combustiongas expands isentropically back to the original inlet volume, shown at8, where the combustion gas is then discharged. As shown in FIG. 2, thecombustion gas discharges at a pressure above atmosphere, shown at 8,and then the pressure drops to atmosphere as it exhausts from theengine, not shown. The energy that could be available by expanding fromexhaust pressure to atmospheric pressure, represented by the differencebetween 8 and 5 shown in FIG. 5, is wasted.

The advantage of the Diesel cycle compared to the Otto cycle is that thecompression ratio can be made much higher than that for the Otto Cycle,because the fuel is not mixed in the air, and therefore the rise duringcompression in temperature will not ignite the fuel until after the fuelis injected at the high pressure. In general, this increase incompression ratio for the Diesel Cycle enables the Diesel cycle toachieve higher efficiencies than are possible with the Otto Cycle.

The compression ratio for the Otto Cycle is usually limited to about 10to 1, corresponding to a pressure ratio of about 25 to 1. The reason forthis is that at higher ratios the fuel air mixture becomes so hot thatthe explosion occurs before the mixture is fully compressed. Thispreignition or detonation actually decreases the power output.

In the Diesel engine the fuel injection occurs after compression, andonly air is being compressed during the compression cycle. Therefore,typical compression ratios are 23 to 1, corresponding to pressure ratiosof 82 to 1. This is the basic reason why the Diesel cycle is moreefficient than the Otto cycle.

A further cycle is the Brayton or Joule cycle, as shown in FIG. 3 [PriorArt]. In the Brayton cycle, air is drawn into a compressor atatmospheric pressure, shown at 9, and then compressed to a highpressure, shown at 10. Fuel is injected into the compressed air in thecombustor, where it burns at nearly a constant pressure (except forfriction losses in the combustor) to form a combustion gas, shown at 11.The combustion gas expands isentropically back to atmospheric pressure,shown at 12. In this case, the expansion to atmospheric pressure isadvantageous, and the theoretical efficiency is like the Otto cycleabove in that the theoretical efficiency is equal to 1−(V₂/V₁) _((K-1))where V₁/V₂ is again the volume ratio of specific volume at atmosphericpressure divided by the specific volume at the pressure at which burningstarts. The Brayton cycle is the cycle commonly used in gas turbines,and is limited in efficiency by the fact that the temperature of the gasentering the turbine is nearly the same as the combustion temperature.Therefore the combustion temperatures possible in a gas turbine systemare usually limited to approximately 2300 to 2600° F. However, theBrayton cycle does have an advantage over the Otto cycle in thatcomplete expansion back to essentially atmosphere is achieved.

A disadvantage of the Brayton cycle is that as pressure ratios orcompression ratios are increased the temperature leaving the compressorand entering the combustor becomes higher. Therefore, less fuel energycan be added because of the temperature limit of the turbine. For thisreason, although efficiency can be increased by increasing the pressureratio in a gas turbine cycle, the output gradually decreases as higherpressure ratios are used. Therefore, it is common practice to limit thepressure ratio in industrial gas turbines to about 10 to 20 atmospheres.

Table 1 shows typical theoretical performance calculations for theBrayton cycle, based on air standard data and constant mass flow throughthe cycle.

TABLE 1 A B C D E F G H I 1 P2/P1 32 32 32 32 32 32 32 32 2 T1 520 520520 520 520 520 520 520 3 T3 2810 2810 2810 2810 2810 2810 2810 2810 4P1/J 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 5 V1 13.08913.089 13.089 13.089 13.089 13.089 13.089 13.089 6 EFF COMP 1 0.9 0.850.9 0.9 0.9 0.9 0.9 7 COOL FACT 1 1 1 0.9 0.8 0.7 0.6 0.5 8 N/(N-1) CO3.463 3.1167 2.94355 3.463 3.895876 4.462429 5.1945 6.2334 9 (N-1)/N CO0.288767 0.320852 0.339726 0.288767 0.256682 0.224597 0.192511 0.16042810 N COMP 1.406009 1.472434 1.514522 1.406009 1.345319 1.289651 1.2384071.19108 11 EFF TURB 1 0.9 0.85 0.9 0.9 0.9 0.9 0.9 12 N/(N-1) TU 3.4633.847778 4.074118 3.847778 3.847778 3.847778 3.847778 3.847778 13 (N-1)N TU 0.288767 0.25989 0.245452 0.25989 0.25989 0.25989 0.25989 0.2598914 N TURB 1.406009 1.351151 1.325297 1.351151 1.351151 1.351151 1.3511511.351151 15 W IN 212.1196 251.5701 276.9102 235.6885 221.0261 207.4814194.9616 183.3819 16 V1/V2 11.76285 10.52493 9.858518 11.76285 13.1463614.6926 16.4207 18.35205 17 T2/T1 2.72043 3.0404 3.245924 2.720432.434134 2.177968 1.94876 1.743674 18 T2 1414.624 1581.008 1687.881414.624 1265.75 1132.543 1013.355 906.7106 19 HEAT IN 330.8437 291.3941266.0545 330.8437 366.1417 397.725 425.9845 451.2699 20 V3 2.2103422.210342 2.210342 2.210342 2.210342 2.210342 2.210342 2.210342 21 WEXPAN 421.3532 395.5742 381.6844 395.5742 395.5742 395.5742 395.5742395.5742 22 NET WORK 209.2335 144.0041 104.7742 159.8857 174.5481188.0928 200.6127 212.1923 23 EFF 0.632424 0.49419 0.393807 0.4832670.476723 0.472922 0.470939 0.470212 A J K L M N O P 1 P2/P1 32 32 32 3232 32 32 2 T1 520 520 520 520 520 520 520 3 T3 2810 2810 2810 2810 28102810 2810 4 P1/J 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 5 V113.089 13.089 13.089 13.089 13.089 13.089 13.089 6 EFF COMP 0.9 0.9 0.90.9 0.9 0.9 0.9 7 COOL FACT 0.4 0.3 0.2 0.1 0.05 0.04 0.03 8 N/(N-1) CO7.79175 10.389 15.5835 31.167 62.334 77.9175 103.89 9 (N-1)/N CO0.128341 0.096256 0.06417 0.032085 0.016043 0.012834 0.009626 10 N COMP1.147237 1.106508 1.068571 1.033149 1.016304 1.013001 1.009719 11 EFFTURB 0.9 0.9 0.9 0.9 0.9 0.9 0.9 12 N/(N-1) TU 3.847778 3.8477783.847778 3.847778 3.847778 3.847778 3.847778 13 (N-1) N TU 0.259890.25989 0.25989 0.25989 0.25989 0.25989 0.25989 14 N TURB 1.3511511.351151 1.351151 1.351151 1.351151 1.351151 1.351151 15 W IN 172.6651162.7406 153.5437 145.0155 140.9852 140.197 139.4146 16 V1/V2 20.5105722.92296 25.6191 28.63234 30.26937 30.60784 30.9501 17 T2/T1 1.5601711.39598 1.249068 1.117617 1.057174 1.045484 1.033922 18 T2 811.289725.9096 649.5154 581.1609 549.7306 543.6515 537.6396 19 HEAT IN473.8944 494.1378 512.2509 528.4577 535.9099 537.3512 538.7766 20 V32.210342 2.210342 2.210342 2.210342 2.210342 2.210342 2.210342 21 WEXPAN 395.5742 395.5742 395.5742 395.5742 395.5742 395.5742 395.5742 22NET WORK 222.9091 232.8337 242.0305 250.5587 254.589 255.3772 256.159623 EFF 0.470377 0.471192 0.472484 0.47132 0.475059 0.476252 0.476447

In Table 1 the following definitions are used:

P₂/P₁ is the pressure ratio

T1=air inlet temperature in ° R (degrees Rankin)

T3=combustion temperature in ° R

P1/J=inlet pressure in lbs/ft²/778.2

V1=inlet specific volume in ft³/lb.

EFF COMP is polytropic compression efficiency

COOL FACT is a factor that is multiplied by (N−1)/N, where(N−1)/N=(k−1)/K/comp EFF., and (K−1)/K=0.2888. This factor shows a newvalue of (N−1)/N that simulates continuous intercooling during thecompression process. Actual intercooling is a step-by-step process, butthis simulation shows the approximate effect of intercooling.

(N−1)/N CO=(K−1)/K/EFF COMP×COOL FACT

N Comp. is the polytropic exponent used in the equation for work

EFF TURB is the polytropic efficiency of the turbine

(N−1)/N TU=(k−1)/K×EFF TURB

WIN=Compressor work in Btu/lb

V1/V2=Compression ratio

T2/T1=Ratio compressor discharge temperature/inlet temperature

T2=Compressor discharge temperature ° R

Heat IN=Heat Input from T2 to T3, assuming specific heat=0.2371 Btu/lb°F

V3=Specific volume at turbine inlet in cu.ft./lb

W EXPAN=Turbine work output in Btu/lb

NET WORK=W EXPAN-WIN

EFF=NETWORK/HEAT IN=cycle efficiency

In column C, the Brayton cycle efficiency is listed as 0.494. This ishigher than the actual efficiency of a gas turbine because leakagelosses, cooling air losses, pressure drop in the combustor, and lossesdue to kinetic energy of the gases leaving the turbine column D, whereefficiencies of 85% are used for compressor and turbine, were excluded.

It would be advantageous if one could combine the constant volume orexplosion cycle as shown in the Otto cycle at the high pressure end, andat the same time expand the volume all the way to atmospheric pressureat the exhaust end, as shown FIG. 4. FIG. 4 is a theoretical completeexpansion cycle.

An almost complete expansion cycle was made by Sargent, in which the airinlet to the engine is throttled to take in less air volume and therebyallow for an increase in volume in the exhaust. However, this Sargentcycle was not a success in a reciprocating engine because of the highmechanical friction losses.

Thus, there is a need for a complete expansion cycle that is suitablefor use in a reciprocating engine, which substantially avoids wastingenergy due to exhaust pressures that are greater than atmosphericpressure.

There is also a need for an improved combustion chamber that is capableof supplying compressed gas to a turbine blade at temperaturessignificantly below the combustion temperature of the fuel being burned.

There is a further need for an improved apparatus for supplying acompressed gas having significantly reduced friction losses.

Electrical power plants utilizing turbine engines to drive electricalgenerators produce large amounts of combustion gasses which containcarbon dioxide and byproducts such as nitrogen oxides. Furthermore, theexhaust gas from conventional turbine engines usually has a temperatureof about 700° F. to about 1240° F. Typically a Rankin cycle system isused to recovery valuable energy from the exhaust gas. However,efficient low temperature vapor turbines usually cannot be used becausethe exhaust temperature from a conventional turbine engine is too high.Exhaust temperatures from conventional turbine engines usually requirethe use of an expensive steam turbine to recover the energy.

Thus, there is a need for an electrical generating power plantcomprising more efficient turbines to reduce the quantity of combustiongasses produced, and for turbine engines having exhaust temperaturesuitable for use in driving low temperature vapor turbines.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a substantiallycomplete expansion cycle that is suitable for use in a gas turbineengine, that substantially avoids wasting energy due to exhaustpressures that are greater than atmospheric pressure.

Another objective of the present invention is to provide an engine thatutilizes a substantially complete expansion cycle, which substantiallyavoids wasting energy due to exhaust pressures that are greater thanatmospheric pressure.

A further objective of the present invention is to provide an improvedcombustion chamber that is capable of producing a pressurized gas fordriving a turbine blade at a temperature significantly below thecombustion temperature of the fuel being burned in the combustionchamber.

Another objective of the present invention is to provide an improvedcombustion chamber for producing a pressurized gas, which hassignificantly reduced friction losses.

A further objective of the present invention is to provide a method forforming a pressurized gas, which can be converted to mechanical energyin an engine.

Another objective of the present invention is to provide an electricalgenerating power plant comprising more efficient turbines to reduce thequantity of combustion gasses produced.

A further objective is to provide an electrical generating power plantcomprising a turbine engine an efficient low temperature vapor turbinedriven by the exhaust from said turbine engine.

The above objectives and other objectives are surprisingly achieved bythe following.

Provided is a novel combustion chamber for producing a pressurized gascomprising:

a wall structure defining an interior chamber;

a first reflecting surface for reflecting a pressure wave within saidinterior chamber;

a second reflecting surface for reflecting said pressure wave withinsaid interior chamber, wherein said first and second reflecting surfacesbeing constructed and arranged to resonate said pressure wave in saidinterior chamber;

at least one first inlet for introducing a first gas into said interiorchamber; and

at least one outlet from said interior chamber for drawing off apressurized gas from said interior chamber.

Also provided is a novel turbine engine comprising:

at least one combustion chamber;

at least one compressor constructed and arranged to provide a compressedgas to said at least one combustion chamber; and

at least one turbine blade constructed and arranged to be driven by apressurized gas formed in said combustion chamber; wherein saidcombustion chamber comprises:

a wall structure defining an interior chamber;

a first reflecting surface for reflecting a pressure wave within saidinterior chamber;

a second reflecting surface for reflecting said pressure wave withinsaid interior chamber, wherein said first and second reflecting surfacesbeing constructed and arranged to resonate said pressure wave in saidinterior chamber;

at least one first inlet for introducing a first gas into said interiorchamber;

at least one second inlet for introducing said compressed gas into saidinterior chamber, said second inlet being connected to said at least onecompressor; and

at least one outlet from said interior chamber for drawing off saidpressurized gas from said chamber and being constructed and arranged tosupply said pressurized gas to said at least one turbine blade.

The present invention also provides a novel electrical generating powerplant comprising:

at least one turbine engine;

at least one electrical generator connected to said turbine engine;wherein said turbine engine comprises:

at least one combustion chamber;

at least one compressor constructed and arranged to provide a compressedgas to said at least one combustion chamber; and

at least one turbine blade constructed and arranged to be driven by apressurized gas formed in said combustion chamber; wherein saidcombustion chamber comprises:

a wall structure defining an interior chamber;

a first reflecting surface for reflecting a pressure wave within saidinterior chamber;

a second reflecting surface for reflecting said pressure wave withinsaid interior chamber, wherein said first and second reflecting surfacesbeing constructed and arranged to resonate said pressure wave in saidinterior chamber;

at least one first inlet for introducing a first gas into said interiorchamber;

at least one second inlet for introducing said compressed gas into saidinterior chamber, said second inlet being connected to said at least onecompressor; and

at least one outlet from said interior chamber for drawing off saidpressurized gas from said chamber and being constructed and arranged tosupply said pressurized gas to said turbine blade.

Also provided is a novel method of forming a pressurized gas having atemperature lower than a combustion temperature of a combustible gasused to form said pressurized gas comprising the steps of:

introducing a combustible gas into a combustion chamber having first andsecond reflecting surfaces that are constructed and arranged to providea resonating pressure wave reflecting between said first and secondreflecting surfaces, said combustible gas being introduced into saidcombustible chamber at a frequency such that said resonating pressurewave ignites said combustible gas to thereby form a resonating pressurewave;

introducing a second gas into said combustion chamber at a location andfrequency such that said pressure wave compresses and combines with saidsecond gas to form a pressurized gas having a temperature lower than acombustion temperature of said combustible gas; and

withdrawing said pressurized gas from said combustion chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 [Prior Art] illustrates a graph of the pressure vs. volume for anOtto cycle engine.

FIG. 2 [Prior Art] illustrates a graph of the pressure vs. volume for aDiesel cycle engine.

FIG. 3 [Prior Art] illustrates a graph of the pressure vs. volume for aBrayton cycle engine.

FIG. 4 illustrates a graph of the pressure vs. volume for a theoreticalcomplete expansion cycle.

FIG. 5 illustrates a schematic diagram of an engine utilizing a highpressure cycle according to the present invention.

FIG. 6 illustrates a diagram of a resonating pressure wave in acombustion chamber having a length that is one-half of the wavelength ofthe pressure wave.

FIG. 7 illustrates a diagram of a resonating pressure wave in acombustion chamber having a length that is one wavelength of thepressure wave.

FIG. 8 illustrates a graph of the pressure vs. volume for a highpressure turbine cycle according to the present invention.

FIG. 9 is a cross-sectional view of a rotary distributor valve accordingto the present invention.

FIG. 10 is a cross-sectional view of a rotary distributor valveaccording to the present invention.

FIG. 11 illustrates a schematic diagram of an engine utilizing a highpressure cycle according to the present invention.

FIG. 12 illustrates a schematic diagram of an engine utilizing a highpressure cycle according to the present invention.

FIG. 13 illustrates a schematic diagram of an engine utilizing a highpressure cycle according to the present invention.

FIG. 14 illustrates a schematic diagram of an engine utilizing a highpressure cycle according to the present invention.

FIG. 15 illustrates a schematic diagram of an engine utilizing a highpressure cycle according to the present invention.

FIG. 16 illustrates a schematic diagram of a power plant according tothe present invention.

FIG. 17 illustrates a cut-away view of six high pressure cycles shown inFIG. 5 arranged circumferentially around the rotor blades.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will be further explained with reference to theattached drawings. The present invention provides a combustion chamberfor producing a pressurized gas, which has significantly reducedfriction losses. Furthermore, the pressurized gas introduced into thecombustion chamber can be provided at a temperature which issignificantly lower than the combustion temperature of the fuel beingburned in the combustion chamber. Moreover, the combustion chamberutilizes detonation of a combustible gas to provide improved burningefficiency and reduced byproducts such as nitrogen oxides.

The improved combustion chamber according to the present invention willbe explained with reference to a turbine engine. However, it will beunderstood by one skilled in the art that the pressurized gas producedby the combustion chamber can be converted to mechanical energy usingother means besides a turbine blade. For example, the pressurized gascan be used to drive a reciprocating piston. The pressurized gas couldalso be used for jet propulsion.

The present invention demonstrates that unexpectedly it is possible toattain the advantages of an explosion cycle at high pressures, and alsoto achieve substantially complete expansion of the exhaust, therebygreatly improving the cycle efficiency of an engine. A combustionchamber can be provided that is capable of supplying pressurized gas toa turbine blade at temperatures significantly below the combustiontemperature of the fuel being burned. By producing a pressurized gashaving a temperature below combustion temperatures, the followingadvantages can be attained:

(1) significantly greater pressure ratios can be utilized in the turbinewhile not exceeding the temperature limits of the turbine blades;

(2) greater amounts of fuel can be burned while not exceeding thetemperature limits of the turbine blades;

(3) net power output of the turbine can be greatly increased; and

(4) at the higher pressure ratios achieved by the combustion chamberaccording to the present invention, specific volumes are lower, therebypermitting shorter turbine blades, that are stronger and easier to coolcompared with longer turbine blades.

FIG. 5 illustrates a cross-sectional view of an embodiment of the highpressure cycle according to the present invention which is used in aturbine engine. On the left end of the shaft shown at 30 is the laststage of a series of axial flow compressor blades, the last blade beingshown at 32. Air is compressed by the compressor blades and dischargedfrom the compressor, shown at 34. After leaving the air compressor, thecompressed air enters a chamber which is divided into two sections by adivider plate, shown at 35. In an upper section, shown generally at 36,fuel is introduced into the chamber through a fuel inlet, shown at 38,and mixes with the air. In the lower section, shown generally at 40, theair remains substantially free-of fuel. The air/fuel mixture isdischarged through the inlet of a valve, shown at 42, into a combustionchamber. The combustion chamber, shown at 47, comprises an explosionchamber, shown generally at 48, and a compression chamber, showngenerally at 52. Any valve that is suitable for controlling the flow ofa compressed gas into the combustion chamber can be utilized.Preferably, the valve is capable of synchronizing the flow of gas intothe combustion chamber with a resonating pressure wave therein, wherebythe valve is open when the combustion chamber pressure is lower thanaverage and closed when the combustion chamber pressure is greater thanaverage. A non-limiting preferred example of a valve is a distributorrotary valve, examples of which are illustrated in FIGS. 9 or 10,described below. Based on the disclosure provided herein, one skilled inthe art will be able to select the desired valve for the desiredapplication.

As shown in FIG. 5, as the rotary valve rotates it alternately opens thevalve to the lower air compression chamber, shown at 44, and the valveto the upper explosion chamber, shown at 46. The air/fuel mixture entersthe explosion chamber shown at 48 and is ignited by a high pressure wavecompressing the mixture, or alternatively by an igniting device, shownat 50, such as a spark plug. The explosion of the air/fuel mixturestarts a pressure wave down the channel of the explosion chamber andcurves around until it compresses air previously introduced through theopen valve 44 (now closed) against the lower valve plate shown at 54.The general area where the air is compressed in the combustion chamberis shown generally at 52. The pressure wave is then reflected back thedirection it came and the pressure wave compresses a new air/fuelmixture to create another explosion in the explosion chamber 48. Thus,there is a continuous alternating cycle between explosions creating apressure wave which compresses air in the air compression chamber andreflections of the pressure wave that compress the air/fuel mixture tocause the explosions. Preferably, the frequency of the explosions iscontrolled to provide a resonating pressure wave in the tube. This meansthat the pressure in the tube alternates between the following twostages:

(A) high pressure in the compression chamber 48 and low pressure in thecompressor chamber 52 during the explosion stage; and

(B) low pressure in the compression chamber 48 and high pressure in thecompressor chamber 52 during the compressing of the air (compressionstage).

Examples of means for adjusting the frequency of explosions in thecombustion chamber include;

(1) adjusting the length of the tube;

(2) adjusting the frequency of the air/fuel mixture entering thecombustion chamber;

(3) adjusting the temperature of gas contained within combustionchamber;

(4) adjusting the amount of air/fuel mixture being supplied to thecombustion chamber;

(5) adjusting the speed of the rotary valve; and

(6) adjusting the relative flow areas, shown at 44 and 46 in theFigures.

The combustion chamber can be adjusted to be a length that provides thedesired resonant frequency. For example, if the length of the tube isone-half of the pressure wave length and the frequency of explosionsresonate, then the pressure at somewhere near the middle of the wavetravel remains practically constant (about an average of the combustionchamber pressure), but is significantly higher than the inlet pressurecoming from the air compressor. Examples of suitable combustion chamberlengths for providing a resonating pressure wave include, but are notlimited, to the following combustion chamber lengths shown in FIGS. 6and 7.

FIG. 6 illustrates a combustion chamber having a length that is one-halfof the wave length of the pressure wave. Between the points E1 and E2 inthe combustion chamber, the pressure variation is significantly lessthan elsewhere in the combustion chamber, such as at the firstreflecting surface R1 or at the second reflecting surface R2. At R1 andR2, the pressure varies from P1 to P3. Between the points E1 and E2, thepressure varies significantly less than between P1 to P3. Thus, the gasflow taker from the combustion chamber between the points E1 and E2 willfluctuate significantly less than the gas flow taken elsewhere from thecombustion chamber. Preferably, the gas flow taken from the combustionchamber is at substantially the average combustion chamber pressure,shown at P2.

FIG. 7 illustrates a combustion chamber having a length that is one wavelength of the pressure wave. Between the points E3 and E4 or the pointsE5 and E6 in the combustion chamber, the pressure variation issignificantly less than elsewhere in the combustion chamber, such as atthe first reflecting surface R1 or at the second reflecting surface R2.At RI and R2, the pressure varies from P1 to P3. Between the points E3and E4 or between E5 and E6, the pressure varies significantly less thanbetween P1 to P3. Thus, the gas flow taken from the combustion chamberbetween the points E3 and E4 or between the points E5 and E6 willfluctuate significantly less than the gas flow taken elsewhere from thecombustion chamber. Preferably, the gas flow taken from the combustionchamber is at substantially the average combustion chamber pressure,shown at P2.

The resonating pressure waves shown in FIGS. 6 and 7 represent acombustion chamber having a constant temperature throughout the lengthof the combustion chamber. However, when a combustion chamber is usedwhere an air/fuel mixture is injected into the combustion chamber at ornear the first reflecting surface R1 and air is injected into thecombustion chamber at or near the second reflecting surface R2, thetemperature will be significantly higher near the first reflectingsurface where combustion is occurring than at the second reflectingsurface. Since the compression wave travels faster as the temperature isincreased, the resonating pressure waves shown in FIGS. 6 and 7 will beskewed away from first reflecting surface R1. Thus, the part of thecombustion chamber defined between E1 and E2 will be farther from thefirst reflecting surface R1 and closer to the second reflecting surfaceR2 than shown in FIG. 6. Similarly, the parts of the combustion chamberdefined between E3 and E4, and between E5 and E6, will be farther fromthe first reflecting surface R1 and closer to the second reflectingsurface R2 than shown in FIG. 7. Based on the disclosure providedherein, one skilled in the art will easily be able to determine thelocation in the combustion chamber that provides a substantiallyconstant gas flow pressure.

As shown in FIG. 5, the outlet from the compression chamber, shown at56, is farther away from the inlet for the air/fuel mixture than it isfrom the inlet for the air. As explained above, since the temperature ofthe exploding air/fuel mixture is much higher than that of the air inthe air compression chamber, the velocity of the pressure wavecorresponding to acoustic velocity in the gas is much higher in thehotter explosion chamber than in the colder compression chamber.Typically, the acoustic velocity is proportional to the square root ofthe absolute temperature. Therefore, the point at which the pressureremains constant in the system with proper tuning will be closer to theair compression chamber portion than it is to the explosion chamberportion of the combustion chamber. The hot exploding air/fuel mixtureforms a hot combustion gas that mixes with the cooler air compressiongases to form a pressurized gas having a temperature somewhere betweenthe explosion temperature (or combustion temperature of the fuel/airmixture) and the air compression temperature. The pressurized gas thenflows out of the combustion chamber through turbine nozzles to drive theturbine blades. The result of this system is that the pressure of thepressurized gas contacting the turbine blades can be considerably higherthan the pressure of the compressed air formed by the air compressor. Inparticular, the exploding air/fuel mixture forms a pressure wave thatacts as a piston to further compress the compressed air introduced intothe compression chamber portion of the combustion chamber to form amixture of twice compressed air and combustion gasses, referred to aspressurized gas. The pressurized gas can be withdrawn from thecombustion chamber at a pressure significantly higher than the pressureof the compressed air entering the combustion chamber. Furthermore, thetemperature of the pressurized gas leaving the combustion chamber issignificantly less than the air/fuel mixture explosion temperature (orcombustion temperature of the air/fuel mixture). Thus, more air/fuelmixture can be burned in the combustion chamber according to the presentinvention while not exceeding the temperature limit of the turbineblades, compared to conventional combustion chambers.

FIG. 8 illustrates a pressure volume diagram that is applicable to thehigh pressure cycle described above. The air enters at a first pressureand volume, shown at 70, and is compressed isentropically to a secondpressure and volume, shown at 72. At this point, approximately one-halfof the air is mixed with fuel and explodes to a high pressure, shown at74. The pressure wave formed expands isentropically and the pressuredecreases to a lower pressure and greater volume, shown at 76.

The energy of expansion is approximately equal to the energy required tocompress the air from the pressure and volume shown at 72 to thepressure and volume shown at 78. This results in an intermediatepressure corresponding to the pressure shown at 80 and 76.

When the hot gas mixes at the pressure and volume shown at 76, with theair at the pressure and volume shown at 78, they end up at a specificpressure and volume shown at 80. From the pressure and volume of thegases shown at 80, the gasses expand to approximately atmosphericpressure, shown at 82, and eventually reduce in specific volume back tothe volume shown at 70, external to the system. The temperature at thepressure and volume shown at 74 can be much higher than the temperatureof the gas that enters the gas turbine because after expansion from thevolume shown at 74 to the volume shown at 76, and mixing with thecompressed air shown at 80, the temperature of the gas is much lower.Therefore, the effective explosion temperature (or combustiontemperature of the fuel/air mixture) is significantly higher than thetemperature of the pressurized gas that contacts the turbine blades.This then makes use of the potential of operating the combustion systemat much higher combustion temperatures than is currently possible with aturbine operating on the Brayton Cycle, because the temperature of thepressurized gas contacting the turbine blades is lower than thecombustion temperature.

The rotary valve illustrated in FIG. 9 has 3 holes, shown at 43. Therotary valve illustrated in FIG. 10 has 5 holes, shown at 45. Thecircles represent the location of the holes in the stationary plate withone hole representing the inlet to the combustion chamber and the otherhole representing the inlet to the air compression chamber.

Preferably, the rotary valve has holes aligned whereby the valve 46 isopen when the valve 44 is closed, and the valve 44 is open when thevalve 46 is closed. For example, if the valve 46 and the valve 44 areplaced in line with the central axis of the rotary valve, as shown inFIG. 5, the rotary valve should have an odd number of holes so thatvalves 46 and 44 are not open at the same time.

Since the explosion can reach a very high temperature, it may benecessary to cool the walls of the chamber. For example, in FIG. 5, acooling jacket is shown at 51, that can be used to cool the explosionchamber portion of the combustion chamber. Optionally, water-cooledwalls can be used for the entire combustion chamber if desired.

The combustion chamber shown in FIG. 5 utilizes a mixture of fuel/air.FIG. 11 illustrates a cross-sectional view of a turbine engine similarto that shown in FIG. 5, with the following modifications. In theturbine shown in FIG. 11, fuel is not introduced into the air chamberpreceding the combustion chamber. Instead, air is introduced tocombustion chamber 47′ through the valve shown at 46′. Fuel isintroduced into the combustion chamber through the fuel inlet shown at100. The fuel mixes with the air in the explosion chamber portion of thecombustion chamber, shown generally at 48′.

When using the combustion chamber shown in FIG. 11, the fuel injectionshould alternate in tune with the air inlet valve to the chamber. Thefuel injection can be timed with an injection pump, if liquid fuel, orwith a valve, if gaseous fuel, so that the fuel enters at approximatelythe same time as the air enters through valve 46.

FIG. 11 shows an optional annular space around the explosion chamber,shown at 102. This annular air space allows the compressed air in theair compression chamber to help cool the wall of the explosion chamber.However, since the explosion temperature can be high, further cooling ofthe explosion chamber wall may be desired.

As shown in FIG. 11, the pressure wave travels to the end of theexplosion chamber, turns, and travels toward the air compressionchamber, shown generally at 52′. The spherical end, shown at 104, maycause a reflection of the pressure wave and disrupt the single frequencyresonating pressure wave in the combustion chamber. This undesirablereflection could be avoided, for example, by using the U tube designshown in FIGS. 5 or 12, or a straight tube as the combustion chamber.FIG. 12 illustrates an annular space, shown at 110 around the combustionchamber. The two curves at the right hand end of the tube serve todeflect the pressure wave smoothly without an intermediate reflection,such as shown in FIG. 12.

The pressurized gas outlet, shown at 58, to the turbine, shown at 60, iscloser to the air compression chamber 52′ than the explosion chamber48′. As discussed previously, the high temperature exploding air/fuelmixture compression wave has a higher acoustic velocity, and thereforein the same time travels farther than the lower temperature compressionwave in the air compression chamber. Therefore, the outlet to theturbine should not be at one-half the total length of the chamber butshould be closer to the air compression end, when a substantiallyconstant pressure is desired and when using a combustion chamber havinga length equal to one-half wavelength of the pressure wave.

Although it is possible to have the fuel injected separately into theexplosion chamber, usually it is more desirable to have the fuel mixedwith the air prior to introducing the air and fuel to the explosionchamber. Therefore in FIG. 5, the fuel inlet 38 connects to the mixingchamber 36 and a divider plate 35 separates the air/fuel mixture fromthe air prior to entering the explosion chamber. This scheme is usuallymore desirable than having the fuel injected directly into the explosionchamber for the following reasons:

(1) The air/fuel mixture is usually more uniformly mixed compared tofuel injection because the air/fuel mixture has time to mix thoroughlybefore the explosion occurs.

(2) The ignition of the air/fuel mixture can be more easily generated bythe pressure wave itself than when using fuel injection. Ignition viathe pressure wave usually provides a more substantially constant volumeexplosion than is possible when using a spark plug to ignite the fuel.Constant volume explosion improves the theoretical efficiency of theexplosion chamber system.

(3) By having the air/fuel thoroughly mixed before the explosion, theexplosion temperatures can be more uniform than when using a flamepropagation created by a spark plug. This is desirable because thevariation of temperature will be considerably less than that when flamepropagation occurs. This has the effect of reducing formation ofnitrogen oxides and other undesirable combustion by-products.

A problem with mixing the fuel and air prior to entering the explosionchamber may be that the air temperature leaving the compressor could betoo high, which can lead to undesirable combustion in the mixingchamber. This could be prevented by intercooling the air going throughthe air compressor so that the temperature of the air leaving the aircompressor is low enough that detonation will not occur in the mixingchamber.

In the Otto Cycle used in automobile engines, where fuel and air aremixed before compression, the limiting value of compression ratio isapproximately 8:1 to 10:1, corresponding to a pressure ratio ofapproximately 25 to 1, to avoid detonation. By intercooling air as itpasses through the compressor, it is possible to limit the temperatureof the air entering the mixing chamber to avoid detonation. This makesit possible to use higher pressure ratios than are normally possiblewith the Otto Cycle used in the automobile engine. If the mixture isthen ignited by the pressure wave returning from the compression end ofthe combustion chamber, the explosion occurs throughout the mixture andcan reach a higher pressure than is possible if it occurs by flamepropagation. In other words, by intercooling the air compressorsignificantly higher pressure ratios can be used while mixing the airand fuel before introducing them into the explosion chamber.

The present invention provides a remarkable advantage because use of thedetonation characteristics of fuel are utilized, rather than attemptingto suppress the detonation characteristics as is usually done inconventional automobile engines.

In FIG. 8, the temperature of the combustion gas at point 74 can be muchhigher than the temperature of the pressurized gas that enters the gasturbines because after expansion from 74 to 76, the combustion gas ismixed with the compressed gas at 78 to form a pressurized gas. Thetemperature of the pressurized gas is less than the temperature of thecombustion gas. Therefore, the effective burning temperature can be muchhigher than the temperature of the pressurized gas that enters the gasturbine. This then makes use of the potential of operating the system atmuch higher temperatures than is currently possible with a gas turbineoperating on the Brayton Cycle.

Performance values for the high pressure cycle according to the presentinvention are shown in the following Table 2. Table 3 illustrates theequations used for determining the performance values shown in Table 2.The calculations are based on what is considered to be the air standardcycle with constant mass flow through the system, and no addition ofmass for the fuel, constant specific heats throughout the cycle andother possible operating conditions.

TABLE 2 A B C D E F G H I J K L M N 1 P2/P1 32 32 32 32 32 32 32 32 3232 32 32 32 2 T1 520 520 400 460 460 460 460 460 460 460 460 520 520 3P1/J 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 2.7201 2.72012.7201 2.7201 2.7201 2.7201 4 T3 4000 4000 4000 4000 4000 4000 4000 40004000 4000 4000 4040 4400 5 EFF. COMP. 1 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.90.9 0.9 0.9 0.9 6 COOL FACT. 1 1 1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 1 1 7N/(N-1) CO 3.463 3.1167 3.1167 3.1167 3.463 3.895875 4.452429 5.19456.2334 7.79175 10.389 3.1167 3.1167 8 (N-1)/N CO 0.288766965 0.3208520.320852 0.320852 0.288767 0.256682 0.224597 0.192511 0.160426 0.1283410.096256 0.320852 0.320852 9 N COMP 1.406008932 1.472434 1.4724341.472434 1.406009 1.345319 1.289651 1.238407 1.19108 1.147237 1.1065081.472434 1.472434 10 EFF TURB 1 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.90.9 0.9 11 N/(N-1) TU 3.463 3.847775 3.847778 3.847778 3.847778 3.8477783.847778 3.847778 3.847778 3.847778 3.847778 3.847778 3.847778 12(N-1)/N TU 0.288768965 0.25989 0.25989 0.25989 0.25989 0.25989 0.259890.25989 0.25989 0.25989 0.25989 0.25989 0.25989 13 N TURB 1.4060089321.351151 1.351151 1.351151 1.351151 1.351151 1.351151 1.351151 1.3511511.351151 1.351151 1.351151 1.351151 14 T2/T1 2.720430224 3.0404 3.04043.0404 2.72043 2.434134 2.177966 1.94876 1.743674 1.560171 1.395983.0404 3.0404 15 T2 1414.623716 1581.008 1216.16 1398.584 1251.3981119.702 1001.865 896.4297 802.0901 717.6788 642.1508 1581.008 1581.00816 P3/P2 2.827607054 2.530032 3.289041 2.660036 3.196425 3.672383.992553 4.462146 4.986971 5.573524 6.229066 2.555332 2.783035 17 P3/P190.48342574 80.96102 105.2493 91.52115 102.2856 114.3162 127.7617142.7887 159.5831 178.3528 199.3301 81.77063 89.05712 18 V1/V211.76284535 10.52493 10.52493 10.52493 11.76285 13.14636 14.6926 18.420718.35205 20.61057 22.92296 10.52493 10.52493 19 V1 13.089 13.08910.06846 11.57873 11.57873 11.57873 11.57873 11.57873 11.57873 11.5787311.57873 13.089 13.089 20 V2 1.112740975 1.243618 0.95663 1.1001240.984348 0.880756 0.788066 0.70513 0.630923 0.564525 0.505115 1.2436181.243618 21 X = V3/V2 0.5 0.509 0.573 0.543 0.568 0.587 0.603 0.6170.628 0.638 0.646 0.5 0.436 22 (1-X)/X 1 0.964637 0.745201 0.8416210.760563 0.703578 0.658375 0.620746 0.592357 0.567398 0.547988 11.293578 23 V3 0.556370488 0.633002 0.548149 0.597367 0.55911 0.5170040.475204 0.435065 0.39622 0.360167 0.326304 0.621809 0.542218 24 P4/P22.088337066 1.908258 2.553853 2.186671 2.475192 2.797871 3.1629523.576572 4.040154 4.564795 5.153344 1.911016 1.944272 25 P4/P30.738552785 0.754243 0.776473 0.764561 0.774362 0.783195 0.7922130.801538 0.810142 0.819014 0.827306 0.747854 0.696616 26 P4/P166.8267661 61.06424 81.72331 69.97348 79.20614 89.53187 101.2145114.4503 129.2849 146.0734 164.907 61.15251 62.21671 27 P4 982.3537557897.6444 1201.333 1028.61 1164.33 1316.118 1487.853 1682.419 1900.4892147.279 2424.133 898.9419 914.5857 28 T4/T2 1.236967851 1.2051691.310986 1.253515 1.299195 1.345996 1.394526 1.444912 1.496676 1.550391.605652 1.205672 1.211694 29 T4C 1749.844058 1905.382 1594.369 1753.1451625.81 1507.114 1397.128 1295.262 1200.469 1112.662 1031.071 1906.1771915.698 30 T4/T3 EXPLO 0.916196417 0.921776 0.929541 0.9254 0.9288110.931858 0.934944 0.938108 0.941006 0.943971 0.946721 0.919514 0.90160431 T4E 3664.785666 3687.102 3718.164 3701.699 3715.242 3727.431 3739.7763752.434 3764.025 3775.883 3786.884 3714.836 3967.06 32 T4 2707.3148622812.277 2811.304 2811.158 2812.607 2810.44 2809.744 2811.337 2810.3822811.804 2811.326 2810.507 2810.092 33 V4 1.019738658 1.159236 0.885891.011235 0.893822 0.790128 0.698755 0.618296 0.547165 0.484523 0.4291141.156834 1.136879 34 HEAT IN 217.9472207 207.5916 268.9407 238.1591263.2193 285.0579 30.8078 322.8526 338.5973 353.0688 365.7222 207.293207.223 35 T5/T4 0.297176567 0.343472 0.31842 0.331528 0.321019 0.3109570.301201 0.291733 0.282637 0.27381 0.265315 0.343343 0.341807 36 T5804.5505359 965.9385 895.1744 931.9758 902.901 873.9255 846.2989820.1596 794.3183 769.8996 745.8858 964.968 960.5091 37 HEAT OUT67.46693206 105.732 117.4058 111.9055 105.0118 98.14172 91.5914685.39383 79.26687 73.47719 67.78352 105.5019 104.4447 38 WORK150.4802886 101.8596 151.6348 126.2537 158.2075 186.9162 213.2163237.4588 259.3304 279.5916 297.9386 101.7911 102.7783 39 EFF.0.690443715 0.490673 0.563451 0.530123 0.601048 0.655713 0.6995110.735502 0.765896 0.79189 0.814658 0.491049 0.495979 40 V5 20.2513518624.31365 22.53245 23.45878 22.72693 21.99759 21.3022 20.64425 19.993819.37915 18.7747 24.28922 24.17699 41 WORK COM 150.8664994 170.8533131.4256 151.1395 148.2878 145.3359 142.3185 139.2644 136.1977 133.1392130.1058 170.8533 170.8533 42 WORK EXP 320.8768874 324.003 336.2501329.7661 335.123 339.8275 344.5533 349.4198 353.787 358.3217 362.4518323.8626 324.5722 43 WORK EXH 19.48231334 30.53217 33.90328 32.3149130.32422 28.34034 26.44881 24.65911 22.88982 21.21793 19.57376 30.4657230.16044 44 NET WORK 150.5280747 122.6175 170.9212 146.3117 156.5112166.1512 175.786 185.4963 194.6994 203.9646 212.7725 122.5435 123.558545 EFF. BY WORK 0.69068297 0.590667 0.635535 0.614344 0.594604 0.5828680.576711 0.574554 0.575018 0.577691 0.581787 0.591161 0.596259

TABLE 3 A B C D E F G H I 1 P2/P1 32 32 32 32 32 32 32 32 2 Y1 520 520400 460 460 460 460 460 3 P1/J 2.7201 2.7201 2.7201 2.7201 2.7201 2.72012.7201 2.7201 4 T3 4000 4000 4000 4000 4000 4000 4000 4000 5 EFF COMP 10.9 0.9 0.9 0.9 0.9 0.9 0.9 6 COOL FACT 1 1 1 1 0.9 0.8 0.7 0.6 7N/(N-1) CO =3.463{circumflex over ( )}B5/B6 =3.463{circumflex over( )}C5/C6 =3.463{circumflex over ( )}D5/D6 =3.463{circumflex over( )}E5/E6 =3.463{circumflex over ( )}F5/F6 =3.463{circumflex over( )}G5/G6 =3.463{circumflex over ( )}H5/H6 =3.463{circumflex over( )}I5/I6 8 (N-1)/N CO =1/B7 =1/C7 =1/D7 =1/E7 =1/F7 =1/G7 =1/H7 =1/I7 9N COMP =1/(B7-1) + 1 =1/(C7-1) + 1 =1/(D7-1) + 1 =1/(E7-1) + 1=1/(F7-1) + 1 =1/(G7-1) + 1 =1/(H7-1) + 1 =1/(I7-1) + 1 10 EFF TURB 10.9 0.9 0.9 0.9 0.9 0.9 0.9 11 N/(N-1) TU =3.463/B10 =3.463/C10=3.463/D10 =3.463/E10 =3.463/F10 =3.463/G10 =3.463/H10 =3.463/I10 12(N-1)/N TU =1/B11 =1/C11 =1/D11 =1/E11 =1/F11 =1/G11 =1/H11 =1/I11 13 NTURB =1/(B11-1) + 1 =1/(C11-1) + 1 =1/(D11-1) + 1 =1/(E11-1) + 1=1/(F11-1) + 1 =1/(G11-1) + 1 =1/(H11-1) + 1 =1/(I11-1) + 1 14 T2/T1=B1{circumflex over ( )}B8 =C1{circumflex over ( )}C8 =D1{circumflexover ( )}D8 =E1{circumflex over ( )}E8 =F1{circumflex over ( )}F8=G1{circumflex over ( )}G8 =H1{circumflex over ( )}H8 =I1{circumflexover ( )}I8 15 T2 =B2{circumflex over ( )}B14 =C2{circumflex over( )}C14 =D2{circumflex over ( )}D14 =E2{circumflex over ( )}E14=F2{circumflex over ( )}F14 =G2{circumflex over ( )}G14 =H2{circumflexover ( )}H14 =I2{circumflex over ( )}I14 16 P3/P2 =B4/B15 =C4/C15=D4/D15 =E4/E15 =F4/F15 =G4/G15 =H4/H15 =I4/I15 17 P3/P1 =B16{circumflexover ( )}B1 =C16{circumflex over ( )}C1 =D16{circumflex over ( )}D1=E16{circumflex over ( )}E1 =F16{circumflex over ( )}F1 =G16{circumflexover ( )}G1 =H16{circumflex over ( )}H1 =I16{circumflex over ( )}I1 18V1/V2 =B1{circumflex over ( )}(1/B9) =C1{circumflex over ( )}(1/C9)=D1{circumflex over ( )}(1/D9) =E1{circumflex over ( )}(1/E9)=F1{circumflex over ( )}(1/F9) =G1{circumflex over ( )}(1/G9)=H1{circumflex over ( )}(1/H9) =I1{circumflex over ( )}(1/I9) 19 V1=13.089{circumflex over ( )}B2/520 =13.089{circumflex over ( )}C2/520=13.089{circumflex over ( )}D2/520 =13.089{circumflex over ( )}E2/520=13.089{circumflex over ( )}F2/520 =13.089{circumflex over ( )}G2/520=13.089{circumflex over ( )}H2/520 =13.089{circumflex over ( )}I2/520 20V2 =B19/B18 =C19/C18 =D19/D18 =E19/E18 =F19/F18 =G19/G18 =H19/H18=I19/I18 21 X = V3/V2 0.5 0.509 0.573 0.543 0.568 0.587 0.603 0.617 22(t-x)/x =(1-B21)/B21 =(1-C21)/C21 =(1-D21)/D21 =(1-E21)/E21 =(1-F21)/F21=(1-G21)/G21 =(1-H21)/H21 =(1-I21)/I21 23 V3 =B20{circumflex over( )}B21 =C20{circumflex over ( )}C21 =D20{circumflex over ( )}D21=E20{circumflex over ( )}E21 =F20{circumflex over ( )}F21=G20{circumflex over ( )}G21 =H20{circumflex over ( )}H21=I20{circumflex over ( )}I21 24 P4/P2 =((B16 + B22)/B22 + =((C16 +C22)/(C22 + =((D16 + D22)/(D22 + =((E16 + E22)/(E22 + =((F16 +F22)/(F22 + =((G16 + G22)/(G22 + =((H16 + H22)/(H22 + =((I16 +I22)/(I22 + B16{circumflex over ( )}0.711233)){circumflex over ( )}3.463C16{circumflex over ( )}0.711233)){circumflex over ( )}3.463D16{circumflex over ( )}0.711233)){circumflex over ( )}3.463E16{circumflex over ( )}0.711233)){circumflex over ( )}3.463F16{circumflex over ( )}0.711233)){circumflex over ( )}3.463G16{circumflex over ( )}0.711233)){circumflex over ( )}3.463H16{circumflex over ( )}0.711233)){circumflex over ( )}3.463I16{circumflex over ( )}0.711233)){circumflex over ( )}3.463 25 P4/P3=B24/B16 =C24/C16 =D24/D16 =E24/E16 =F24/F16 =G24/G16 =H24/H16 =I24/I1626 P4/P1 =B1{circumflex over ( )}B24 =C1{circumflex over ( )}C24=D1{circumflex over ( )}D24 =E1{circumflex over ( )}E24 =F1{circumflexover ( )}F24 =G1{circumflex over ( )}G24 =H1{circumflex over ( )}H24=I1{circumflex over ( )}I24 27 P4 =B26{circumflex over ( )}14.7=C26{circumflex over ( )}14.7 =D26{circumflex over ( )}14.7=E26{circumflex over ( )}14.7 =F26{circumflex over ( )}14.7=G26{circumflex over ( )}14.7 =H26{circumflex over ( )}14.7=I26{circumflex over ( )}14.7 28 T4/T2 =B24{circumflex over ( )}0.2888=C24{circumflex over ( )}0.2888 =D24{circumflex over ( )}0.2888=E24{circumflex over ( )}0.2888 =F24{circumflex over ( )}0.2888=G24{circumflex over ( )}0.2888 =H24{circumflex over ( )}0.2888=I24{circumflex over ( )}0.2888 29 T4C =B28{circumflex over ( )}B15=C28{circumflex over ( )}C15 =D28{circumflex over ( )}D15=E28{circumflex over ( )}E15 =F28{circumflex over ( )}F15=G28{circumflex over ( )}G15 =H28{circumflex over ( )}H15=I28{circumflex over ( )}I15 30 T4/T3 EXPLO =B25{circumflex over( )}0.2888 =C25{circumflex over ( )}0.2888 =D25{circumflex over( )}0.2888 =E25{circumflex over ( )}0.2888 =F25{circumflex over( )}0.2888 =G25{circumflex over ( )}0.2888 =H25{circumflex over( )}0.2888 =I25{circumflex over ( )}0.2888 31 T4E =B4{circumflex over( )}B30 =C4{circumflex over ( )}C30 =D4{circumflex over ( )}D30=E4{circumflex over ( )}E30 =F4{circumflex over ( )}F30 =G4{circumflexover ( )}G30 =H4{circumflex over ( )}H30 =I4{circumflex over ( )}I30 32T4 =B31{circumflex over ( )}B21 + =C31{circumflex over ( )}C21 +=D31{circumflex over ( )}D21 + =E31{circumflex over ( )}E21 +=F31{circumflex over ( )}F21 + =G31{circumflex over ( )}G21 +=H31{circumflex over ( )}H21 + =I31{circumflex over ( )}I21 +B29{circumflex over ( )}(1-B21) C29{circumflex over ( )}(1-C21)D29{circumflex over ( )}(1-D21) E29{circumflex over ( )}(1-E21)F29{circumflex over ( )}(1-F21) G29{circumflex over ( )}(1-G21)H29{circumflex over ( )}(1-H21) I29{circumflex over ( )}(1-I21) 33 V4=53.282{circumflex over ( )}B32/B27/144 =53.282{circumflex over( )}C32/C27/144 =53.282{circumflex over ( )}D32/D27/144=53.282{circumflex over ( )}E32/E27/144 =53.282{circumflex over( )}F32/F27/144 =53.282{circumflex over ( )}G32/G27/144=53.282{circumflex over ( )}H32/H27/144 =53.282{circumflex over( )}I32/I27/144 34 HEAT IN =(B4-B15){circumflex over( )}0.1686{circumflex over ( )}B21 =(C4-C15){circumflex over( )}0.1686{circumflex over ( )}C21 =(D4-D15){circumflex over( )}0.1686{circumflex over ( )}D21 =(E4-E15){circumflex over( )}0.1686{circumflex over ( )}E21 =(F4-F15){circumflex over( )}0.1686{circumflex over ( )}F21 =(G4-G15){circumflex over( )}0.1686{circumflex over ( )} =(H4-H15){circumflex over( )}0.1686{circumflex over ( )}H21 =(I4-I15){circumflex over( )}0.1686{circumflex over ( )}I21 G21 35 T5/T4 =1/(B1{circumflex over( )}B24){circumflex over ( )}B12 =1/(C1{circumflex over( )}C24){circumflex over ( )}C12 =1/(D1{circumflex over( )}D24){circumflex over ( )}D12 =1/(E1{circumflex over( )}E24){circumflex over ( )}E12 =1/(F1{circumflex over( )}F24){circumflex over ( )}F12 =1/(G1{circumflex over( )}G24){circumflex over ( )}G12 =1/(H1{circumflex over( )}H24){circumflex over ( )}H12 =1/(I1{circumflex over( )}I24){circumflex over ( )}I12 36 T5 =B32{circumflex over ( )}B35=C32{circumflex over ( )}C35 =D32{circumflex over ( )}D35=E32{circumflex over ( )}E35 =F32{circumflex over ( )}F35=G32{circumflex over ( )}G35 =H32{circumflex over ( )}H35=I32{circumflex over ( )}I35 37 HEAT OUT =0.2371{circumflex over( )}(B36-B2) =0.2371{circumflex over ( )}(C36-C2) =0.2371{circumflexover ( )}(D36-D2) =0.2371{circumflex over ( )}(E36-E2)=0.2371{circumflex over ( )}(F36-F2) =0.2371{circumflex over( )}(G36-G2) =0.2371{circumflex over ( )}(H36-H2) =0.2371{circumflexover ( )}(I36-I2) 38 WORK =B34-B37 =C34-C37 =D34-D37 =E34-E37 =F34-F37=G34-G37 =H34-H37 =I34-I37 39 EFF =B38/B34 =C38/C34 =D38/D34 =E38/E34=F38/F34 =G38/G34 =H38/H34 =I38/I34 40 V5 =53.282{circumflex over( )}B36/14.7/144 =53.282{circumflex over ( )}C36/14.7/144=53.282{circumflex over ( )}D36/14.7/144 =53.282{circumflex over( )}E36/14.7/144 =53.282{circumflex over ( )}F36/14.7/144=53.282{circumflex over ( )}G36/14.7/144 =53.282{circumflex over( )}H36/14.7/144 =53.282{circumflex over ( )}I36/14.7/144 41 WORK COM=2.7201{circumflex over ( )}B19/(B9-1)/ =2.7201{circumflex over( )}C19/(C9-1)/ =2.7201{circumflex over ( )}D19/(D9-1)/=2.7201{circumflex over ( )}E19/(E9-1)/ =2.7201{circumflex over( )}F19/(F9-1)/ =2.7201{circumflex over ( )}G19/(G9-1)/=2.7201{circumflex over ( )}H19/(H9-1)/ =2.7201{circumflex over( )}I19/(I9-1)/ B5{circumflex over ( )}B1{circumflex over ( )}B8-1)C5{circumflex over ( )}C1{circumflex over ( )}C8-1) D5{circumflex over( )}D1{circumflex over ( )}D8-1) E5{circumflex over ( )}E1{circumflexover ( )}E8-1) F5{circumflex over ( )}F1{circumflex over ( )}F8-1)G5{circumflex over ( )}G1{circumflex over ( )}G8-1) H5{circumflex over( )}H1{circumflex over ( )}H8-1) I5{circumflex over ( )}I1{circumflexover ( )}I8-1) 42 WORK EXP =B27{circumflex over ( )}B33{circumflex over( )}B10/5.40417/ =C27{circumflex over ( )}C33{circumflex over ( )}C10/=D27{circumflex over ( )}D33{circumflex over ( )}D10/5.40417/=E27{circumflex over ( )}E33{circumflex over ( )}E10/ =F27{circumflexover ( )}F33{circumflex over ( )}F10/5.40417/ =G27{circumflex over( )}G33{circumflex over ( )}G10/ =H27{circumflex over ( )}H33{circumflexover ( )}H10/5.40417/ =I27{circumflex over ( )}I33{circumflex over( )}I10/5.40417/ (B13-1){circumflex over ( )}(1-1/B26{circumflex over( )}B12) 5.40417/(C13-1){circumflex over ( )} (D13-1){circumflex over( )}(1-1/D26{circumflex over ( )}D12) 5.40417/(E13-1){circumflex over( )} (F13-1){circumflex over ( )}(1-1/F26{circumflex over ( )}F12)5.40417/(G13-1){circumflex over ( )} (H13-1){circumflex over( )}(1-1/H26{circumflex over ( )}H12) (I13-1){circumflex over( )}(1-1/I26{circumflex over ( )}I12) (1-1/C26{circumflex over ( )}C12)(1-1/E26{circumflex over ( )}E12) (1-1/G26{circumflex over ( )}G12) 43WORK EXH =2.701{circumflex over ( )}(B40-B19) =2.701{circumflex over( )}(C40-C19) =2.701{circumflex over ( )}(D40-D19) =2.701{circumflexover ( )}(E40-E19) =2.701{circumflex over ( )}(F40-F19)=2.701{circumflex over ( )}(G40-G19) =2.701{circumflex over( )}(H40-H19) =2.701{circumflex over ( )}(I40-I19) 44 NET WORK=B42-B41-B43 =C42-C41-C43 =D42-D41-D43 =E42-E41-E43 =F42-F41-F43=G42-G41-G43 =H42-H41-H43 =I42-I41-I43 45 EFF BY WORK =B44/B34 =C44/C34=D44/D34 =E44/E34 =F44/F34 =G44/G34 =H44/H34 =I44/I34

In Table 2:

Row 1 shows the pressure ratio of 32 through the air compressor.

Row 2 shows the inlet temperature in degrees Rankine.

Row 3 shows the value of 14.7 psia×144/778.2. T3 is the peak temperaturereached in the explosion in degrees Rankine, and should be achievable.Actually, if stoichiometric combustion is achieved, then the values forT3 should be higher than 4000° R.

Row 5 shows compressor polytropic efficiency.

Row 6 shows a cooling factor which represents intercooling with thenumber 1 being the case with no intercooling in the compressor.

Row 7 represents the value of N/(N−1) where N is the equivalent ratio ofspecific heat at constant pressure to the specific heat at constantvolume when compression is polytropic rather than isentropic, and thevalue shown is the value that occurs with the polytropic efficiency andcooling factor shown.

Row 8 is the inverse of Row 7.

Row 9 is the ratio of specific heats and the equivalent value shown forthe actual polytropic exponent, or the exponent as affected by continualprocess intercooling.

Row 10 shows polytropic efficiency of expansion in the turbine.

Rows 11, 12 and 13 correspond to Row 7, 8 and 9, but as calculated forthe expansion curve for the 5 turbine.

Row 14 is the ratio of compressor discharge temperature to compressorinlet temperature.

Row 15 is the compressor discharge temperature in degrees Rankine.

Row 16 is the ratio for the pressure at the peak of the explosion to thepressure at the outlet from the compressor.

Row 17 shows the ratio of peak pressure in the explosion to atmosphericinlet pressure. Note that the values of P3/P1 go as high as 199 incolumn L. Currently diesel engine peak cylinder pressures reachapproximately this same value.

Row 18 V1/V2 is the ratio of inlet volume to the volume aftercompression in the compressor. V1 is the specific volume of air at thecorresponding pressure P1 and T1. This is stated in cubic feet perpound. V2 is the specific volume after compressing in the compressor.

Row 21 X is the ratio of the volume of air entering the explosionchamber to the volume of air entering the compression chamber end of thechamber.

Row 23 V3 is the specific volume of the gas at peak explosion pressure.

Row 24 P4/P2 is the ratio of the pressure after expansion from the peakexplosion pressure to the pressure leaving the compressor.

Row 25 P4/P3 is the ratio of the pressure of the mixture leaving thecombustion chamber to the peak pressure of the explosion.

Row 26 P4/P1 is the expansion ratio passing through the turbine aftercombustion.

Row 27 P4 is the pressure at turbine inlet in lbs/square inch absolute.

Row 28 T4/T2 is the ratio of turbine inlet temperature to compressordischarge temperature.

Row 29 T4C is the temperature in the compressor end of explosion chamberin degrees Rankine.

Row 30 T4/T3 is the ratio of the temperature laving the explosionchamber to the temperature at the peak of explosion.

Row 31 T4E is the temperature of the exploding gas mixture before itmixes with the air in the opposite end of the chamber.

Row 32 T4 is the temperature of the mixture leaving the combustionchamber and entering the turbine.

In these calculations, the value of X has been adjusted whereby thevalue of T4 is approximately 2810° R (2350° F.) which is a usable modernturbine inlet temperature.

Row 33 V4 is the specific volume of the gas mixture as it leaves thechamber.

Row 34 the heat in is the heat input from the fuel heating the air orair fuel mixture from a temperature of T2 to a temperature of T3.

Row 35 T5/T4 is the ratio of turbine exhaust temperature to turbineinlet temperature.

Row 36 T5 is the exhaust temperature from the system in degrees Rankine.

Row 37 the heat out represents the specific heat at constant pressuretimes the quantity (T5-T1).

Row 38 the work output is in BTU's per pound, and is calculated from thedifference between the heat input and the heat output. This work outputis correct for the theoretical condition as shown in column B.

Row 39 the cycle efficiency equals the quantity item 34-item 37 dividedby item 34. The efficiency calculation is correct for the theoreticalcase shown in column B. The efficiency is an approximation and may beslightly lower due to intercooling and inefficiency in the compressionand expansion in this cycle.

Row 40 V5 is the specific volume of the gas at exhaust.

Row 41 the work of compression is calculated by the compression formulaat the value of N shown on Row 9.

Row 42 the work of expansion is the work output from the turbine ascalculated based on the N value shown on item 13.

Row 43 the work from the exhaust represents theoretical work that islost as the volume at the exhaust shrinks to the volume at the inlettemperature.

Row 44 the net work equals the work of expansion item 42-item 41-item43.

Row 45 the efficiency is simply the net work divided by item 34, theheat input.

The efficiencies shown in Table 2 do not take fully into account otherlosses that should be accounted for in an actual turbine, and thereforethe efficiencies may be slightly lower than those shown above. Despitethese additional losses not shown in the Table 2, the remarkableincrease in efficiency shown in Table 2 compared to Table 1 is verysignificant and startling. For example, in comparing column c in Table 2with column c in Table 1, the increase in efficiency is almost 20%. Thisdifference is even more accentuated when using an intercooled system.For example comparing column j in Table 2 with column j in Table 1, theincrease in efficiency is 22%.

The turbine and compressor polytropic efficiencies of 0.9 are rathertypical of what is attained in gas turbines today.

The efficiency of the explosion process was not calculated and wasassumed to be 100%. The following important factors should be notedregarding the explosion process.

1. There will be less heat loss from the combustion chamber according tothe present invention than what occurs in a Diesel engine cylinder. Thereason for this is that with a gas piston in the explosion chamber thewalls can be much hotter than the walls in a diesel engine cylinderwhere lubrication is required. Therefore, the radiation or convectionheat loss should be much less in the high pressure cycle according tothe present invention than in a Diesel cycle.

2. There should be a very low friction loss in the present inventionbecause compression is achieved using a compression wave instead of apiston. Furthermore, if the average velocity in the explosion chamber isat most about 200 feet per second, then friction loss becomesnegligible.

3. The efficiency of a traveling pressure wave is very high. Forexample, a tidal wave or tsunami can travel thousands of miles acrossthe ocean with very little diminution of energy.

4. When a detonation type of explosion is made to occur, as in thepresent invention, the explosion should be very close to constantvolume.

In Table 2, columns D and E show the considerable improvement inefficiency and output compared to column C, which is made possible byrefrigerating the inlet air to 400° R or 460° R.

Refrigerating the inlet air to the compressor, as shown on columns Fthrough L, makes possible liquid injection intercooling. This liquidinjection intercooling is made possible because refrigerating the inletair removes the moisture from the air stream, and makes it possible toinject water and evaporate it within the compressor, thereby performingeffective intercooling with very little losses.

In columns C through L, the percentage of air in the explosion processhas been adjusted to allow the turbine inlet temperature, T4, to beapproximately 2810° R which is a usable turbine inlet temperature inmodern day turbines. Note that in both Table 1 and 2, the variousdegrees of intercooling maintain fairly constant cycle efficiency, butthe net work output increases very greatly with more intercooling.Therefore, liquid injection intercooling and inlet refrigeration becomevery important factors in increasing the power output of a given sizeturbine.

Columns M and N show the effect of increasing the explosion temperaturecloser to the stoichiometric value when compared to column C. Thisdemonstrates that the efficiency will increase with higher explosiontemperatures at the same turbine inlet temperature by virtue of the factthat the X value or ratio of V3/V2 is adjusted to produce the sameturbine temperature.

The peak pressure values shown on line 17 appear to be quite high.However, it should be noted that current peak pressure ratios on dieselengines are as high as 200. Therefore, these high peak pressures shouldbe reasonably achievable.

An important factor in comparing Table 2 with Table 1 is that the gasvolume introduced into the turbine shown on line 20 in the Brayton Cycleversus V4 on line 33 on table 2 shows that the volume of the gasentering the turbine is much less in Table 2 than it is in Table 1. Forexample, on column J which is an intercooled case, the volume enteringthe turbine in Table 2 is 0.547 cubic feet per lb whereas the volume ofV3 on column J for the Brayton Cycle is 2.210 cubic feet per lb. This isa ratio of 4 to 1. The significance of this is that the turbine bladesin the high pressure cycle according to the present invention can beapproximately one-fourth of the length of turbine blades for the BraytonCycle. A short blade length means that the turbine blade stresses aresignificantly lower and they will be significantly easier to cool thanthe longer blades for the Brayton Cycle. This in turn means that higherturbine inlet temperatures could be used, which is an importantpractical advantage.

An important factor in the high pressure cycle according to the presentinvention is that exhaust temperatures can be much lower than thosegenerally achievable in the Brayton Cycle turbines in use today. Forexample, in column J line 36, the exhaust temperature from the cycle is794° R or 334° F.

Typical exhaust temperatures from modern gas turbines range from 700° F.to 1240° F. In contrast, an exhaust temperature from a turbine engineaccording to the present invention is significantly lower, on the orderof about 300° F. to about 500° F.

Vapor turbine cycles typically operate efficiently in the range of from800 to 160° F. inlet temperature. Thus, the exhaust from the turbineengine according to the present invention can be used directly to drivea vapor turbine cycle.

In general, high exhaust temperatures correspond to low compressorpressure ratios, and low exhaust temperatures occur with higher pressureratios. However, in the turbine engine according to the presentinvention, the exhaust pressure can also be adjusted by adjusting theamount of air being compressed in the air compression chamber. Ingeneral, the more air being mixed with and compressed by the combustiongas compression wave, the lower the exhaust temperature.

Because of the great demand for higher efficiency gas turbine cycles, itis today increasingly common practice to use a combined cycle in whichthe exhaust gas is used to heat a Rankine cycle system, and produceadditional power and increased efficiency. Typically those cyclesutilizing exhaust gas temperatures of 1100° F. require that a steamturbine cycle be used to recover the exhaust energy. This is veryexpensive, and high pressure steam turbines are usually not efficient.Also, high pressure steam turbines cannot economically use condensingtemperatures very close to atmospheric temperature because the volumeexpansion ratio through such a steam turbine is extremely high.

However, if the exhaust temperature from the gas turbine is as low as334° F., then this heat can be conveniently used in a low temperaturevapor turbine cycle, using a working fluid such as isobutane. This cycleattains a significantly higher turbine efficiency than a steam turbine,and also permits utilizing condensing temperatures very close toatmospheric temperatures. This also has the significance that the heatof condensation of the water vapor in the exhaust can be recovered.Therefore, the overall cycle efficiency can be significantly higher thanthat for other combined cycles in use today.

In gas turbine cycles in use today, it is common practice to use coolingair supplied by the compressor to be injected into the first stageturbine disk 126 and out through holes 129 in the turbine blades 128,thereby cooling the blades 128 so that higher inlet temperatures can beused. FIG. 13 illustrates diagrammatically how this can be accomplishedusing the high pressure cycle according to the present invention. Inorder to provide air at sufficiently high pressure to force its waythrough the cooling passages 124 in the turbine blades 128, the bladecooling air supply line, shown at 120, is located where the combustionchamber pressure varies greatly, such as near an inlet to thecompression chamber. As shown in FIG. 7, the blade cooling air supplyline 120 can be located in the combustion chamber where the combustionchamber pressure approaches P3, such as between the points E4 and E5,the points R1 and E3, or the points R2 and E6. A check valve 122 canalso be installed in the line 120 to prevent backflow into thecombustion chamber. The pulsating pressure at these locations can behigh enough so that pulses of cooling air are sent to the turbineblades. As pointed out above, the turbine blades 128 can be muchshorter, and therefore much easier to cool than the long turbine bladesrequired for the Brayton Cycle system. Therefore the amount of coolingair required to cool the blades can be greatly reduced compared to aconventional gas turbine, both because less cooling air is required, andbecause with intercooling of the compressor, the air coming from thecompression chamber is colder than it is from the ordinary gas turbinecompressor discharge.

FIG. 14 shows an alternative blade cooling system in which steam is usedto cool the turbine blades. This has several potential advantages. Steamhas a higher heat transfer coefficient than air, and therefore for agiven temperature in the cooling line the cooling becomes moreeffective. As shown in FIG. 14, steam cooling can be supplied by havingthe water jacket around the explosion chamber be fed with a highpressure pump, shown at 130, that keeps the water pressure above theboiling point. The high pressure water can then be expanded through athrottle valve, shown at 132, part of it will flash into steam in thehigh pressure flash tank shown at 134, and this steam can then be sentthrough the line shown at 136 to cool the turbine blades. The water atthe bottom of the flash tank can be returned to the inlet of the highpressure pump using the line shown at 138. An additional water supplypump, shown at 140, can feed make up water into the water return line138. This system is potentially more efficient than the system using airto cool the turbine blades because the heat loss from the explosionchamber is used directly to generate the steam that cools the turbineblades.

Although the steam cooling system described above may be veryattractive, it may also be possible to eliminate use of a water jacketon the explosion chamber simply by increasing the heat transfer from theoutside of the explosion chamber walls. As shown in FIG. 15, theincoming air surrounds the explosion chamber in the air chamber shown at150. The fins, shown at 152, on the combustion wall transmit much moreheat to the air than would be the case if the wall were smooth. Bycalculation, it appears that this scheme of cooling the walls may bemore efficient, and also less costly than using water jackets either fordirect cooling or for providing steam cooling to the blades.

Preliminary estimates of the potential size of the combustion chambersrequired for a high pressure cycle can be made by assuming a mass flowof air into the system and assuming conditions of operation as shown oncolumn J of Table 2.

Assuming a flow of 385 pounds per second at conditions specified oncolumn J. The net output of the turbine is then 194.7 BTUs per pound ofair. The turbine output equals pounds per second times BTUs per poundtimes kilowatts per BTUs per second. The output would then be 385 times194.7 times 1.055 equals 79,000 kilowatts.

The volume flow to the combustor equals 385 times 0.6309 cubic feet perpound at the compressor outlet or equals 242.9 cubic feet per second. Atwhat might be considered a reasonable velocity of 200 feet per secondthe flow area would be 242.9/200, which equals 1.214 square feet.

If six combustors 300 are used, as shown in FIG. 17, the area for eachequals 1.214/6=0.2024 square feet or the diameter of the chamber equals6.09 inches. This appears to be a reasonable size for a turbine of thiscapacity.

The lengths of the combustors can be estimated by assuming a frequencyof explosions and a mean acoustic velocity of the ignited gas and of thecompressed gas in the compressor section. A mean temperature in theexplosion end might be 3880° R and the acoustic velocity might beapproximately 3005 feet per second. If the distributor valve havingthree holes is rotated at a rotating speed of 1800 RPM, then the waveperiod would be {fraction (1/90)} of a second. At a period of {fraction(1/90)} of a second, one quarter wave length would be 1/90×3005/4=8.35feet.

In the compression end, assuming the mean temperature would beapproximately 981° R, the acoustic velocity should be approximately 1511feet per second. One quarter wave length would then be 4.20 feet. Basedon these calculations, the total length of the combustion chamber shouldthen be (8.35+4.20)=12.55 feet.

These sample calculations indicate that the size of the combustor forthe high pressure cycle can be very reasonable, and can be fitted aroundthe circumference of a turbine producing an output of about 79megawatts.

Although the location in the combustion chamber where the gas mixtureleaves to enter the turbine should be at a constant pressure, it is verylikely that the pressure may not be exactly constant, and somepulsations in the pressure may occur. This may be undesirable if morethan one combustor is used and all combustors fire in unison. Therefore,in order to minimize the pressure pulsation effect on the turbine inletnozzles and blades the explosions in the separate combustion chambersshould be synchronized so that they are out of phase, such as by havingone-half of the combustion chambers being out of phase with the otherhalf. Another solution for minimizing these pulsations at the turbineinlet would be to use slightly different lengths for the combustionchambers and slightly different frequencies of explosions. Either ofthese methods should assure that undesirable turbine blade vibrationscan be avoided.

While a combustion chamber having two gas inlets has been described, itwill be understood by one skilled in the art that the present inventioncan be practiced using one gas inlet. When using one gas inlet asopposed to two or more gas inlets, less gas may be pressurized in theair compression portion of the combustion chamber and the temperature ofthe pressurized gas leaving the combustion chamber will be higher. Thus,a combustion chamber having at least two gas inlets is preferred becausemore gas is compressed in the air compression chamber portion of thecombustion chamber and the temperature of the pressurized gas leavingthe combustion chamber will be significantly lower.

While the location of the gas outlet in the combustion chamber has beendescribed as being located where the combustion chamber pressure issubstantially constant, it will be understood by one skilled in the artthat the gas outlet can be located elsewhere if desired. For example, ifa substantially constant pressure is not required for the desiredapplication, the gas outlet can be located in the combustion chamberwhere the combustion chamber pressure varies significantly. If maximumpressure is the goal, the gas outlet can be located near one of thereflecting surfaces, or other area in the combustion chamber where thecombustion chamber pressure peaks (such as between E4 and E5, R1 and E3,or R2 and E6, in FIG. 7). In such applications, it may be desirable touse a check valve to prevent backflow into the combustion chamber.However, for most applications a constant gas pressure is desired.

While a U-shaped combustion chamber has been described above, it isunderstood by one skilled in the art that the shape of the combustioncan be adjusted as desired. For example, the combustion chamber can besubstantially straight or a combination of U-shapes. If desired, thecombustion chamber can have a circular shape or a spiral shape thatsurrounds the turbine. The main concern is that the combustion chamberbe constructed and arranged to provide at least one resonating pressurewave therein. Furthermore, the combustion chamber can have varyingdimensions along the length thereof. For example, the volume per setlength of the combustion chamber located near a reflecting surface canbe greater than the volume per set length of the combustion chamberelsewhere, as shown in FIG. 11. In general, the greater the volume perset length of combustion chamber the lower the pressure of the gascontained therein. Preferably, the side walls of the combustion chamber,in the direction of the pressure wave travels, have substantially around tube shape, as used in the Example. However, the side walls of thecombustion chamber can also have as square, triangular, hexagonal,elliptical, or other shapes. Based on the disclosure provided herein,one skilled in the art will be able to select the desired dimensions ofthe combustion chamber to provide the desired resonating pressure waveand pressurized gas.

The high pressure cycle according to the present invention provides manyimportant advantages over previously used gas turbine cycles as listedhere.

1. The high pressure cycle can obtain higher thermal efficiencies thanany cycle heretofore presented. This is important for saving fuel in anenergy hungry world that is gradually depleting all available sources offossil fuel.

2. The high pressure cycle has a higher efficiency and emits less carbondioxide into the atmosphere. This is recognized today as an importantfactor in affecting the climate of the world, and is now considered soimportant that predictions are being made that a carbon tax will beimposed for all of the carbon dioxide emitted from a power plant intothe atmosphere.

3. The use of detonation to ignite the air/fuel mixture providesimproved burning with significantly reduced production of undesirablenitrogen oxides and other combustion by-products.

4. Refrigerating the inlet to a gas turbine removes the moisture fromthe air and thereby permits liquid injection intercooling, which in turnpermits higher efficiency and higher capacity to be attained.

5. Refrigerating the inlet to the gas turbine greatly increases theoutput power for a given size turbine. This means a great deal inreducing the cost per kilowatt power output.

6. Liquid injection intercooling makes premixing of the fuel with theair possible, and assures that detonation in the combustion chamber ispossible. This in turn assures more uniform combustion and lessgeneration of nitrogen oxides in the combustion process.

7. In the high pressure cycle, the specific volume of the gas enteringthe turbine is much lower than that entering typical gas turbine blades.Therefore, the turbine blades can be shorter, easier to cool, and willbe subject to less stress by nature of the blades being shorter.

8. Better blade cooling because of the shorter blades makes higherturbine inlet temperatures possible, which in turn increases potentialturbine efficiency.

9. The higher efficiency of the high pressure cycle assures lowerexhaust temperatures, which in turn assures higher overall efficienciesfor combined cycles, because lower expansion ratios for the Rankinecycle can be used.

10. In the combined cycle, the use of a steam turbine can be avoided,and it is possible to use isobutane as the working fluid in the Rankinecycle which is run from the exhaust of the gas turbine. This permitscondensing at much lower exhaust temperatures than can be used in asteam cycle, and in turn permits recovery of water from the exhaust.Recovery of water becomes more and more important as water becomes ascarce commodity throughout the world.

The present invention also provides an improved electrical powergenerating plant comprising at least one of the novel turbines describedherein above driving an electrical generator. Any conventionalelectrical generator can be used to convert the mechanical energy of theturbine to electrical power. The power plant utilizing the improvedturbine engines is capable of producing significantly less carbondioxide and undesirable combustion by-products such as nitrogen oxides.

Preferably, the improved power plant further contains a Rankine cycle toutilize the energy contained in the exhaust gas of the turbine engine.The turbine engines according to the present invention can be driven toprovide exhaust gasses having a temperature suitable for use in lowtemperature vapor turbine cycle, such as isobutane. Examples of othersuitable low temperature vapor turbine cycles include propane,propylene, or other hydrocarbons, as well as fluorocarbons, andchlorofluorocarbons, of which there are many compounds commerciallyavailable. A low temperature vapor cycle typically operates at atemperature of about 400° F. or less.

The exhaust from a turbine engine according to the present invention issufficiently low enough for directly driving a low temperature vaporcycle. This is a remarkable improvement because low temperature vaporturbine cycles are significantly more efficient and less expensive thanhigh temperature vapor turbine cycles, such as steam.

FIG. 16 illustrates an example of power plant according to the presentinvention. Air enters the system through the air inlet saturation coolershown at 201. An air inlet fan shown at 202 can be used to draw the airinto the system. The air can then be cooled by passing through the airinlet refrigeration coils shown at 203. The cooled air can be compressedusing the compressor shown at 204. The air can also be intercooled inthe compressor so as to control the temperature of the compressed airleaving the compressor down to a temperature where fuel can be injectedinto or mixed with the compressed air without causing combustion priorto entering the combustion chamber. The compressed air can be furthercompressed and combusted by using the resonating combustion chambershown at 205. This combustion chamber can be any one or combination ofcombustion chambers described herein above. After being compressed andcombusted, the air can be used to drive a turbine, shown at 206. Theturbine can be used to drive an electrical generator shown at 207.

The air inlet refrigeration coils can be refrigerated, for example, byusing the low stage refrigerant compressor shown at 208, the high stagerefrigerant compressor shown at 209, and the refrigerant condenser shownat 210.

The exhaust from the turbine in the present invention can surprisinglybe made low enough to drive a low temperature vapor cycle. As shown inFIG. 16, the exhaust from the turbine is used to vaporize isobutane inthe isobutane superheater shown at 211. The superheated isobutane can beused to drive the low pressure vapor turbine engine shown at 217. Thelow pressure vapor turbine engine can be used to drive an electricalgenerator shown at 218. The exhaust from the low pressure vapor turbineengine can be heated in the liquid heater shown at 213 and thentransferred to the liquid heater and boiler shown at 212. Hot gasleaving the isobutane superheater 211 is passed through the liquidheater and boiler 212. The heated isobutane from the liquid heater andboiler 212 can be used to drive a high pressure vapor turbine shown at215. The high pressure turbine can be used to drive an electricalgenerator shown at 216.

Exhaust from the liquid heater and boiler can be expelled through theexhaust stack with the induced draft fan shown at 214.

Isobutane usually exhausts from turbine 217 at temperatures well abovethe saturation or condensing temperature. Therefore, this isobutaneexhaust can be used in the liquid heater 219, which preheats liquidisobutane coming from boiler feed pump 220 before it enters gas heatedheater and boiler 212.

After leaving the liquid heater 213 the isobutane condenses to liquid incondenser 219 and the liquid then flows to pump 220, from whence it ispumped into liquid heater 213 to be preheated before entering boiler212.

The air condenser 219 is cooled by air drawn over the condenser coils219 by the induced draft fan 222.

Before passing through condensor coils 219, the air is cooled to nearlythe wet bulb temperature by passing the air through air saturator 221.The saturator 221 is cooled by water sprayed over the opening of thesaturator surfaces. The water flows down through the surfacescountercurrent to the air flow, and evaporates into the air, therebycooling the air to nearly the wet bulb temperature.

Since the wet bulb temperature may be as high as 20 to 30° Fahrenheitbelow the ambient dry bulb temperature, the cooled air condenses theisobutane in condenser 219 to a much lower temperature than would bepossible if ambient air was circulated over the condensor coils.

The lower condensing temperature achieved increases power output fromisobutane turbine 217, and thereby increases power cycle efficiency.

The invention will be further explained using the following non-limitingexamples.

EXAMPLE

A combustion chamber was formed using a 4 inch diameter tube having alength of approximately 20 feet. The inlet air was controlled by arotary valve which alternately opened and closed the supply of air froman air compression system.

At the opposite end of the tube was an air compressor check valve, whichallowed air to enter when the pressure wave was less than the averagepressure in the combustion chamber and automatically close when thepressure wave was greater than the average pressure in the combustionchamber. The exhaust outlet from the combustion chamber wasapproximately at the middle of the tube. High frequency pressuretransducers were installed at both ends of the tube, and also at themiddle where the exhaust left through a throttling valve. The pressureswere recorded on a high speed oscillograph with pressure plotted againsttime.

By adjusting the frequency of the rotary inlet valve and fuel flow, theexplosions of the fuel/air mixture could be made to resonate. By actualmeasurements, the explosion pressure varied up and down, and thepressure at the opposite air inlet end also varied with the explosionpressure transmitted from the explosion at the fuel air mixture inletend. The pressure at the exhaust near the middle of the chamber wassubstantially constant when the timing of the pressure wave wascontrolled to resonate so that the length of the chamber wasapproximately one-half the wave length of the explosion wave.

By experimenting and adjusting the frequency of the wave so that itresonated, the pressure ratio between the exhaust pressure and the inletpressure was 1.04. A pressure ratio of 1.04 in a combustion processprovides a significant increase in the efficiency of a gas turbinecycle, compared to one which had constant pressure combustion orsomewhat less than constant pressure combustion due to friction in thecombustion chamber causing a pressure drop between the inlet and theoutlet to the turbine nozzles.

One of the critical problems in the experimental chamber was that theair inlet check valve could not be made to survive the high frequenciesused in the explosion chamber.

However, in the design proposed above, the inlet distributor valvecontrols the flow both to the explosion chamber and to the aircompression chamber. This can be accomplished as shown in FIGS. 9 and 10by using a distributor valve with either three or five holes in it, sothat the inlet hole to the explosion chamber opens alternately with theinlet hole to the air compression chamber. By using a return channel,the whole system is in effect folded so that the inlet to the explosionchamber and the inlet to the air compression chamber are both at thesame end, and therefore can be controlled by a distributor valve motorthat is operated at the correct frequency to cause resonatingexplosions.

While the present invention has been described in detail and withreference to specific embodiments, it is apparent to one of ordinaryskill in the art that various changes and modifications can be madetherein without departing from the scope and spirit of the claimedinvention.

What is claimed is:
 1. A turbine engine comprising: at least onecombustion chamber; at least one compressor constructed and arranged toprovide a compressed gas to said at least one combustion chamber; atleast one turbine blade constructed and arranged to be driven by apressurized gas formed in said combustion chamber; and a conduitconnected to the combustion chamber in a location where the combustionchamber pressure varies and being constructed and arranged to supply thecompressed gas to the turbine blade to thereby cool the turbine blade;wherein said combustion chamber comprises: a wall structure defining aninterior chamber; an explosion chamber being disposed within saidinterior chamber; a first reflecting surface for reflecting a pressurewave within said interior chamber; a second reflecting surface forreflecting said pressure wave within said interior chamber, wherein saidfirst and second reflecting surfaces being constructed and arranged toresonate said pressure wave in said interior chamber; at least one firstinlet for introducing a first gas into said explosion chamber, saidfirst inlet being located where the pressure in said combustion chambervaries, and said first inlet comprising a first inlet valve forcontrolling the flow of said first gas into said explosion chamber, saidfirst inlet valve being constructed and arranged to open and close insync with said resonating pressure wave whereby said first inlet valveis open when lower than average interior chamber pressures are prevalentagainst said first inlet valve and closed when higher than averageinterior chamber pressures are prevalent against said first inlet valve;at least one second inlet for introducing said compressed gas into saidinterior chamber being located where a pressure varies in saidcombustion chamber, and said second inlet comprising a second inletvalve for controlling the flow of said second gas into said interiorchamber, said second inlet valve being constructed and arranged to openand close in sync with said resonating pressure wave whereby said secondinlet valve is open when lower than average interior chamber pressuresare prevalent against said second inlet valve and closed when higherthan average interior chamber pressures are prevalent against saidsecond inlet valve, said second inlet being connected to said at leastone compressor; and at least one outlet from said interior chamber fordrawing off said pressurized gas from said chamber and being constructedand arranged to supply said pressurized gas to said at least one turbineblade, wherein said first inlet valve and said second inlet valvecomprise a rotary valve.
 2. A turbine engine according to claim 1,wherein said outlet being located in said interior chamber where thepressure of said resonating pressure wave remains substantiallyconstant, whereby said pressurized gas has a substantially constantpressure.
 3. A turbine engine according to claim 2, wherein said firstreflecting surface defines a wall of said walled structure and saidfirst reflecting surface contains said first inlet.
 4. A turbine engineaccording to claim 1, wherein said gas outlet is located closer to saidsecond reflecting surface than said first reflecting surface.
 5. Aturbine engine according to claim 1, wherein said second reflectingsurface defines a wall of said walled structure and said secondreflecting surface contains said second inlet.
 6. A turbine engineaccording to claim 1, wherein said first inlet is constructed andarranged such that when said first gas comprises a combustible gas andis introduced into said combustion chamber through said first inlet saidfirst gas is ignited by said compression wave and forms a compressionwave that resonates in said chamber, and said second inlet isconstructed and arranged such that said compressed gas introduced intothe combustion chamber through said second inlet is further compressedby said compression wave and combines with a combustion gas formed fromcombusting said first gas to thereby form said pressurized gas.
 7. Aturbine engine according to 1, wherein said rotary valve alternatelyopens said first inlet valve and said second inlet valve.
 8. A turbineengine according to claim 6, wherein said outlet is constructed andarranged to withdraw said pressurized gas at substantially a constantpressure.
 9. A turbine engine according to claim 6, wherein saidinterior chamber is constructed and arranged such that said first andsecond inlets are in line with a rotatable valve.
 10. A turbine engineaccording to claim 9, wherein said interior chamber having substantiallythe shape of a U.
 11. A turbine engine according to claim 1, furthercomprising a plurality of said combustion chambers, at least two of saidcombustion chambers being out of phase.
 12. A turbine engine accordingto claim 1, further comprising an intercooler to control the temperatureof the compressed gas discharged from the compressor.
 13. A turbineengine according to claim 12, wherein said intercooler is adapted tocontrol the temperature of the compressed gas to a temperature lowerthan the ignition temperature of the. compressed gas.
 14. A turbineengine according to claim 1, further comprising a check valve connectedto the conduit to prevent backflow into the combustion chamber.
 15. Aturbine engine according to claim 1, further comprising holes in theturbine blade through which said compressed gas can flow to cool theturbine blade.
 16. A turbine engine according to claim 1, wherein saidconduit is connected to the combustion chamber in a location adjacent tothe first inlet.
 17. An electrical generating power plant comprising: atleast one turbine engine; at least one electrical generator connected tosaid turbine engine; wherein said turbine engine comprises: a pluralityof combustion chambers, at least two of said combustion chambers beingout of phase; at least one compressor constructed and arranged toprovide a compressed gas to said combustion chambers; at least oneturbine blade constructed and arranged to be driven by a pressurized gasformed in said combustion chambers; and at least one conduit connectedto at least one combustion chamber in a location where the combustionchamber pressure varies and being constructed and arranged to supply thecompressed gas to at least one turbine blade to thereby cool the atleast one turbine blade; wherein at least two of said combustionchambers each comprise: a wall structure defining an interior chamber;an explosion chamber being disposed within said interior chamber; afirst reflecting surface for reflecting a pressure wave within saidinterior chamber; a second reflecting surface for reflecting saidpressure wave within said interior chamber, wherein said first andsecond reflecting surfaces being constructed and arranged to resonatesaid pressure wave in said interior chamber; at least one first inletfor introducing a first gas into said explosion chamber, said firstinlet being located where the pressure in said combustion chambervaries, and said first inlet comprising a first inlet valve forcontrolling the flow of said first gas into said explosion chamber, saidfirst inlet valve being constructed and arranged to open and close insync with said resonating pressure wave whereby said first inlet valveis open when lower than average interior chamber pressures are prevalentagainst said first inlet valve and closed when higher than averageinterior chamber pressures are prevalent against said first inlet valve;at least one second inlet for introducing said compressed gas into saidinterior chamber, said second inlet comprising a second inlet valve,said second inlet being connected to said at least one compressor; andat least one outlet from said interior chamber for drawing off saidpressurized gas from said interior chamber and being constructed andarranged to supply said pressurized gas to said turbine blade, whereinsaid first inlet valve and said second inlet valve comprise a rotaryvalve.
 18. An electrical generating power plant according to claim 17,further comprising a low temperature vapor cycle connected to theexhaust of said turbine engine, and said turbine engine being adapted toprovide an exhaust temperature suitable for boiling a fluid into a vaporand driving said low temperature vapor turbine.
 19. An electricalgenerating power plant according to claim 18, wherein said lowtemperature vapor cycle utilizes isobutane.
 20. An electrical generatingpower plant according to claim 17, wherein said outlet being located insaid interior chamber where the pressure of said resonating pressurewave remains substantially constant, whereby said pressurized gas has asubstantially constant pressure.
 21. An electrical power generatingpower plant according to claim 17, wherein said second inlet beinglocated where the pressure in said combustion chamber varies, and saidsecond inlet comprising a second inlet valve for controlling the flow ofsaid second gas into said interior chamber, said second inlet valvebeing constructed and arranged to open and close in sync with saidresonating pressure wave whereby said second inlet valve is open whenlower than average interior chamber pressures are prevalent against saidsecond inlet valve and closed when higher than average interior chamberpressures are prevalent against said second inlet valve.
 22. Anelectrical power generating power plant according to claim 17, whereinsaid first inlet is constructed and arranged such that when said firstgas comprises a combustible gas and is introduced into said combustionchamber through said first inlet said first gas is ignited by saidcompression wave and forms a compression wave that resonates in saidchamber, and said second inlet is constructed and arranged such thatsaid compressed gas introduced into the combustion chamber through saidsecond inlet is further compressed by said compression wave and combineswith a combustion gas formed from combusting said first gas to therebyform said pressurized gas.
 23. An electrical power generating powerplant according to claim 17, further comprising an air cooler connectedto said air compressor to cool air being drawn into said air compressor.24. An electrical power generating power plant according to claim 17,further comprising an intercooler to control the temperature of thecompressed gas discharged from the compressor.
 25. An electrical powergenerating power plant according to claim 24, wherein said intercooleris adapted to control the temperature of the compressed gas to atemperature lower than the ignition temperature of the compressed gas.26. A electrical generating plant according to claim 17, furthercomprising a check valve connected to the conduit to prevent backflowinto the combustion chamber.
 27. A electrical generating plant accordingto claim 17, further comprising holes in the turbine blade through whichsaid compressed gas can flow to cool the turbine blade.
 28. A electricalgenerating plant according to claim 17, wherein said conduit isconnected to the combustion chamber in a location adjacent to the firstinlet.
 29. A turbine engine comprising: at least one combustion chamber;at least one compressor constructed and arranged to provide a compressedgas to said at least one combustion chamber; at least one turbine bladeconstructed and arranged to be driven by a pressurized gas formed insaid combustion chamber; and at least one conduit connected to at leastone combustion chamber in a location where the combustion chamberpressure varies and being constructed and arranged to supply thecompressed gas to at least one turbine blade to thereby cool the atleast one turbine blade; wherein said combustion chamber comprises: awall structure defining an interior chamber; an explosion chamber beingdisposed within said interior chamber; a first reflecting surface forreflecting a pressure wave within said interior chamber; a secondreflecting surface for reflecting said pressure wave within saidinterior chamber, wherein said first and second reflecting surfacesbeing constructed and arranged to resonate said pressure wave in saidinterior chamber; at least one first inlet for introducing a first gasinto said explosion chamber, said first inlet being located where thepressure in said combustion chamber varies, and said first inletcomprising a first inlet valve for controlling the flow of said firstgas into said explosion chamber, said first inlet valve beingconstructed and arranged to open and close in sync with said resonatingpressure wave whereby said first inlet valve is open when lower thanaverage interior chamber pressures are prevalent against said firstinlet valve and closed when higher than average interior chamberpressures are prevalent against said first inlet valve; at least onesecond inlet for introducing said compressed gas into said interiorchamber being located where a pressure varies in said combustionchamber, and said second inlet comprising a second inlet valve forcontrolling the flow of said second gas into said interior chamber, saidsecond inlet valve being constructed and arranged to open and close insync with said resonating pressure wave whereby said second inlet valveis open when lower than average interior chamber pressures are prevalentagainst said second inlet valve and closed when higher than averageinterior chamber pressures are prevalent against said second inletvalve, said second inlet being connected to said at least onecompressor; and at least one outlet from said interior chamber fordrawing off said pressurized gas from said chamber and being constructedand arranged to supply said pressurized gas to said at least one turbineblade.
 30. A turbine engine according to claim 29, further comprising acheck valve connected to the conduit to prevent backflow into thecombustion chamber.
 31. A turbine engine according to claim 29, furthercomprising holes in the turbine blade through which said compressed gascan flow to cool the turbine blade.
 32. A turbine engine according toclaim 29, wherein said conduit is connected to the combustion chamber ina location adjacent to the first inlet.
 33. An electrical generatingpower plant comprising: at least one turbine engine; at least oneelectrical generator connected to said turbine engine; wherein saidturbine engine comprises: a plurality of combustion chambers, at leasttwo of said combustion chambers being out of phase; at least onecompressor constructed and arranged to provide a compressed gas to saidcombustion chambers; at least one turbine blade constructed and arrangedto be driven by a pressurized gas formed in said combustion chambers; atleast one conduit connected to at least one combustion chamber in alocation where the combustion chamber pressure varies and beingconstructed and arranged to supply the compressed gas to at least oneturbine blade to thereby cool the at least one turbine blade; wherein atleast two of said combustion chambers each comprises: a wall structuredefining an interior chamber; an explosion chamber being disposed withinsaid interior chamber; a first reflecting surface for reflecting apressure wave within said interior chamber; a second reflecting surfacefor reflecting said pressure wave within said interior chamber, whereinsaid first and second reflecting surfaces being constructed and arrangedto resonate said pressure wave in said interior chamber; at least onefirst inlet for introducing a first gas into said explosion chamber,said first inlet being located where the pressure in said combustionchamber varies, and said first inlet comprising a first inlet valve forcontrolling the flow of said first gas into said explosion chamber, saidfirst inlet valve being constructed and arranged to open and close insync with said resonating pressure wave whereby said first inlet valveis open when lower than average interior chamber pressures are prevalentagainst said first inlet valve and closed when higher than averageinterior chamber pressures are prevalent against said first inlet valve;at least one second inlet for introducing said compressed gas into saidinterior chamber comprising a second inlet valve, said second inletbeing connected to said at least one compressor; and at least one outletfrom said interior chamber for drawing off said pressurized gas fromsaid chamber and being constructed and arranged to supply saidpressurized gas to said turbine blade.
 34. A electrical generating plantaccording to claim 33, further comprising a check valve connected to theconduit to prevent backflow into the combustion chamber.
 35. Aelectrical generating plant according to claim 33, further comprisingholes in the turbine blade through which said compressed gas can flow tocool the turbine blade.
 36. A electrical generating plant according toclaim 33, wherein said conduit is connected to the combustion chamber ina location adjacent to the first inlet.